Core for a synchronizer blocker ring with bent lugs

ABSTRACT

A support for a synchronizing ring for the synchronization of gears, in which the stops for coupling to the clutch are formed from lugs which are bonded integrally to the sprocket ring or ring-shaped core. The support has a simple structure and can be produced economically.

BACKGROUND OF THE INVENTION

The present invention relates to a support for a synchronizing ring forgear synchronization, with a ring-shaped body having a conical contactsurface, an outer sprocket and stops for coupling to the clutch.

Various types of support are known for synchronizing rings, thesesupports differing especially by the selection of the material therefor.As far as design is concerned, the supports consist substantially of aring-shaped body, which has a sprocket on the outside for positivelocking with the corresponding clutch. There are several lugs orpockets, usually three displaced by 120°, on the outside of thering-shaped body serving as stops for locking of the synchronizing ringto the clutch.

Synchronizing rings of this type are usually produced by a castingprocess, however, it has been proposed to produce synchronizing rings bya punching and drawing method. For example, French Pat. No. 1,553,343describes such a method, wherein first a hat-shaped object is producedby the deep-drawing method, the edge of which is provided with asprocket in the subsequent process steps and the bottom of which isremoved. In the last process step, three pockets are applied in thering-shaped body, these pockets serving as stops for coupling to thegear-shift sleeve. However, this synchronizing ring could not fulfillall the requirements qualitatively that were fulfilled by asynchronizing ring produced by the casting method. Thus, for example,the transition from the ring-shaped body to the sprocket ring had arounded portion on the inside, which is undesirable because it cannot beutilized for the synchronization process. The pockets also reduce theconical contact surface.

The task of the present invention is to provide a support for asynchronizing ring, the support having an extremely simple structurewhich can be produced economically, and the stops are to be designed insuch a way that they do not have an adverse influence on thesynchronization surface.

SUMMARY OF THE INVENTION

According to the present invention, the problem of the above task issolved in the case of a support of the type mentioned at the outset byforming the stops from fins that are integrally bound to the sprocketring or to the ring-shaped body and lie in the same direction as thesurface of the ring-shaped body. Lying in the same direction means herethat the fins extend in the axial direction and run tangentially to thesurface of the ring-shaped body. They may lie entirely or only partiallyagainst the surface. In the case of this type of stop, the production ofthe synchronizing ring is possible only by using a punching,deep-drawing, bending, and stamping process. The transition from thering-shaped body to the sprocket ring is formed as a sharp corner bysubjecting the ring-shaped body to compression and calibration.

In order to be able to form the fins on the sprocket ring, a free spaceis provided next to each fin where the tools can be introduced duringworking. It is expedient if every other tooth were removed from thesprocket ring. Furthermore, it is advantageous when the material of thesprocket ring is removed to form the free space on the left and right ofeach fin, the removal being of such an extent that the distance betweena line that connects the remaining surfaces and the edge of the conicalring-shaped portion is about the half the thickness of the fins. Ifnecessary, the fins can also be provided with pockets.

In the method for the production of the synchronizing ring with lugs onthe sprocket ring, first a ring is punched from a deep-drawable materialstrip. This ring is drawn to a conical ring-shaped configuration with anouter edge. This is followed by axial forming and sizing of the conicalring-shaped part to the ring-shaped body with simultaneous sizing of theconical contact surface. Then the sprocket and the fin stops or lugs arepunched from the outer edge, followed by bending of the fin stops andfinally, the tooth profiles will be pressed to their final form. Theforming and sizing of the tooth profiles leads to a sufficient surfacehardness of the teeth without subsequent machining, since when theslanting top parts are stamped, the surface finish is sufficiently hard,especially on the tooth profile. This method is extremely simple and issuperior to all other methods known in the art. The pushing back of theconical ring part with sizing of the contact frictional cone is ofspecial importance. As a result of this, the transition between thering-shaped body and the sprocket ring will be a very sharp corner, sothat the friction lining to be applied can be inserted right up to thecorner. Thus, the full width of the ring-shaped body is available forthe synchronization process.

In the method of production of the synchronizing ring, in which the finsare integrally bound to the ring-shaped body, first a ring isprestamped, the ring having inward extending fins on its inside edge.The ring is drawn to a conical ring-shaped part and the fins are broughtto lie against the ring-shaped part by bending. Then the conicalring-shaped body is formed by final axial pressing with simultaneousforming and sizing of the conical friction cone. Finally, the sprocketwheel is punched and the tooth profile is stamped and cut.

DESCRIPTION OF THE DRAWINGS

The following are shown:

FIG. 1 shows a top plan view of the synchronizing ring;

FIG. 2 shows a section through the synchronizing ring taken on the line2--2 of FIG. 1;

FIG. 3 shows enlarged detail X of FIG. 1;

FIG. 4 shows a section of a synchronizing ring with a pocket in the lug;and

FIGS. 5 to 9 show schematically the individual process steps in theproduction of the synchronizing ring.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Synchronizing ring 1 shown in FIGS. 1 and 2 has a core 2, which consistssubstantially of a ring-shaped body 3 with a toothed rim 4. Since core 2is to be produced by a punching and stamping process, it was notpossible to attach the usual stop lugs onto the ring-shaped body 3.Also, the ring-shaped body 3 should not be interrupted by pockets forcoupling purposes, as this would reduce the synchronizing surface. Forthis reason, stops 5 are produced which consist of bent lugs 6. Thetoothed rim 4 is interrupted in three places and, instead of the omittedteeth, projecting lugs 6 are present which, when bent over, provide thenecessary stops for the synchronizing ring. The lugs lie tangentially tosurface 17 (FIGS. 3 and 4) of the ring-shaped body 3.

In order to facilitate the bending process, a free space 15 (FIG. 1) isprovided next to each lug. This is achieved by removing the neighboringteeth. In addition, a part of the spline rim 16 is removed. The contactsurface 14 of the synchronizing ring is formed by a friction lining 7consisting of paper friction material, the friction lining beingprovided with axial grooves 8.

Section X of FIG. 1 is shown enlarged in FIG. 3. Here the shape of theindividual teeth 9 can be clearly recognized. However, above all it isintended to show the position of lugs 6. The material of the spline rim16 is also removed on either side of each lug 6. The surfaces 10 and 11produced in this way run parallel to the outside surface of lugs 6. Ifone connects the two surfaces 10 and 11 with an imaginary line 12, thenthe distance Z between line 12 and edge 13 of the ring-shaped body 3 isabout half of the lug thickness d. This dimensional relationship isfavorable when bending lugs 6.

Lugs 6 lie in an axial direction, tangentially to surface 17 ofring-shaped body 3. The edge chamfer is designated as 18, and 19designates the leading edge of ring-shaped body 3. The friction liningis not shown in FIG. 3.

FIG. 4 shows a portion of a synchronizing ring 20 in a perspective view.Friction lining 7 with grooves 8 is placed on ring-shaped body 3.Splined rim 16 is provided with teeth 9. Lugs 21 lie adjacent surface 17of ring-shaped body 3 and are formed in the shape of forks having twoprongs 22 and 23, a pocket 24 lying between the prongs.

The method for the production of the synchronizing ring with the lugs onthe spline rim 16 is carried out in the steps shown in FIGS. 5 to 9.First, a ring 30 is blanked from a deep-drawable strip of material (FIG.5). Using a deep-drawing process, this ring 30 is drawn to a conicalring-shaped part 31 with an outer edge 32 (FIG. 6). Then the conicalring-shaped part 31 is formed and sized in the axial direction and, atthe same time, the conical contact surface 33 is also formed and sized(FIG. 7). Then the ring-shaped body 3 is ready. It should be noted that,during the forming and sizing, a ring-shaped body 3 is produced having asharp edge 34 at the transition from the ring-shaped body 3 to thesplined rim 16. Then tooth rim 4 and lugs 6 are blanked out (FIG. 8).The lugs 6 are subsequently bent and the chamfers are pressed to theirfinal form (FIG. 9).

The production of a synchronizing ring with lugs on the ring-shaped core3 proceeds substantially according to the same principle of the method.However, it should be observed when ring 30 is prepunched, this must bepunched with lugs lying toward the inside and that the bending of thesefins must be carried out before forming the conical ring-shaped core 3and forming and sizing of the friction contact cone 33.

The new support for a synchronizing ring is produced by an extremelysimple method utilizing cold forming without the use of cuttingmachines. Experiments showed that the new support fulfills its taskcompletely.

We claim:
 1. Support for a synchronizing ring for gear synchronizationwith a ring-shaped core having an outer surface and a conical contactsurface, an outer sprocket and stops for coupling to a synchronizingclutch, characterized by the fact that the stops are formed from lugswhich are integrally bonded to a toothed rim of said outer sprocket forthe ring-shaped core, said lugs extending in the same direction as saidouter surface of the ring-shaped core, and a free space formed on eitherside of each lug, preferably by removing the neighboring teeth. 2.Support according to claim 1, characterized by the fact that thetransition from the ring-shaped core to the toothed rim is a sharpcorner.
 3. Support according to claim 1, characterized by the fact that,in order to form the free space on opposite sides of each lug, thematerial of the toothed rim was removed to provide surfaces on theopposite sides of the lug which when connected by a line, the distancebetween the line and the inner edge of said lug is about half of the lugthickness.
 4. Support according to claim 3, characterized by the factthat the lugs have pockets.
 5. Support for a synchronizing ring for gearsynchronization with a ring-shaped core having an outer surface and aconical contact surface, an outer sprocket and stops for coupling to asynchronizing clutch, characterized by the fact that the stops areformed from lugs which are integrally bonded to a toothed rim of saidouter sprocket for the ring-shaped core, said lugs extending in the samedirection as said outer surface of the ring-shaped core, each of saidlugs being initially formed to extend radially outwardly from thering-shaped core and has a pair of parallel outer edges, said lug havingtwo prongs defining a central pocket.
 6. Support according to claim 5,characterized in the fact that said lugs are bent to lie tangentially tothe outer surface of said core.
 7. Support according to claim 6,characterized by the fact that the outer sprocket is formed from atoothed rim, wherein the teeth adjacent said lugs are removed as well asadditional material from the core rim to facilitate bending of the lugs.8. Support according to claim 7, characterized by the fact that thesurfaces of said core defined by the removed material are parallel tothe outside surface of the corresponding lug.